This invention relates to filter systems and more particularly to a fluid filter bypass monitoring system which, during both filtering and filter regenerating operations, assists in proper sealing between dirty and clean fluid sides of the system and, at the same time, assists in recovering residual fluid filtering materials.
It is known in the filtration art to use various types of arrangements to seal the lateral edges of longitudinally advancable filter media. Examples include relying on the weight of drive chains to urge the filter media against support members as disclosed in Hirs, U.S. Pat. No. 3,087,620 and Anderson, U.S. Pat. No. 5,008,007; using resilient sealing strips as disclosed in Hindi, U.S. Pat. No. 3,358,834; special vacuum box sealing members as disclosed in Ishigaki, U.S. Pat. No. 3,677,411; dam members on the undersides of the filter media which interact with underlying shelf members as disclosed in Lee, U.S. Pat. No. 4,220,539, and even inflatable seal tubes as disclosed in Bratten, U.S. Pat. No. 5,601,729. Each of the aforementioned seal techniques has disadvantages. Particularly the use of inflatable seal tubes is subject to failure if the tubes leak or burst.
It is also known to provide inflatable seals to seal space between adjacent parallel surfaces and to test the effectiveness of the seal by measuring pressure in chambers formed between the seal and the sealed interfaces. Examples of such seals are disclosed in Godfrey, U.S. Pat. No. 4,214,760 and Brooking, U.S. Pat. No. 4,908,179. In both of these patents, the testing mechanism accomplishes testing when the surfaces to be sealed are in sealed position, the testing being accomplished by a comparatively complex series of alternatively spaced test probes passing through an enlarged upper end of a flexible seal above the inflatable portion of such flexible seal, the distal ends of the probes extending through each flexible seal into a chamber which is formed between the flexible seal and the members to be sealed so as to measure pressure in such formed chamber. Not only is such an arrangement comparatively complex and costly in construction, operation and maintenance, but in addition, the testing measurement function is of questionable value since it punctures a portion of the flexible seal material and testing is accomplished upon actual sealing rather than prior to such sealing.
Despite the efforts of the prior art, there has remained a need for reliable measures to prevent dirty liquid from circumventing the lateral edges of a longitudinally movable, elongated filter medium and entering a clean filtrate chamber.